Correction device

ABSTRACT

An orthodontic appliance can easily achieve and ensure movement of correction target tooth row in a desired direction and achieve highly predictable treatment is provided while anchorage is satisfactorily ensured. A correction device includes a grip member formed to fit to an inner shape of an oral cavity of a patient so as to grip and cover a tooth row, gum parts, and alveolar bone parts of the patient. The correction device includes a first piece  20  covering an area extending from a crown part to a periphery of a cervical part of a correction target tooth and a second piece included in the grip member. The correction device further includes a force applying member  30  provided to connect the first piece  20  to the second piece  10  and configured to move the correction target tooth in a desired direction.

TECHNICAL FIELD

The present invention relates to correction devices, and particularly toan orthodontic appliance placed in the oral cavity of a patient tocorrect tooth alignment of the patient.

BACKGROUND ART

Various orthodontic appliances to correct tooth alignment of patientshave been devised. Examples of known fixed-type orthodontic appliancesinclude holding arches and multi-brackets. Examples of knownremovable-type orthodontic appliances include expansion plates andaligners. On the other hand, in order to correct the entire toothalignment and to correct bimaxillary protrusion, for example, facemasks, headgears, etc. as extraoral anchorage appliances may be used. Inrecent years, a concept called skeletal anchorage has been introduced,and various experiments have been undertaken to achieve highlypredictable orthodontic treatment.

CITATION LIST Patent Document

-   [Patent Document 1] Japanese Unexamined Patent Publication No.    2009-279022-   [Patent Document 2] Japanese Unexamined Patent Publication No.

2012-223587

SUMMARY OF THE INVENTION Technical Problem

In the background art, in the case of correction using, for example, aholding arch, a partial tooth row and a partial gum are used as ananchorage, thereby using the force of a wire placed between tooth rowsfacing each other to move tooth row misalignment of which is to becorrected (correction target tooth row). However, since the holding archis fixed, a large area contacting with the gum is not possible from theviewpoint of cleanability. The anchorage of the holding arch is weak,and is easily displaced. In the case of the multi-bracket, the returningforce of a wire placed on the buccal side or on the lingual side of atooth row is used to apply certain force to the tooth row, therebyattempting to correct tooth alignment. However, in order to applydesired force only to the correction target tooth row, highly technicaland complicated work, e.g., the shape and the installation of a wire,setting the magnitude of the returning force, is required. Therefore,the multi-bracket is not a technique which can be easily used by anyorthodontic doctors. In addition, even when the wire is carefully setwith prediction, the influence of the reaction force applied to a toothrow adjacent to the correction target tooth row may cause undesirablemovement of the adjacent tooth row. The multi-bracket is suitable formovement of a tooth row in buccal-lingual directions, but difficultlymoves a tooth row in distal-mesial directions. Since the multi-bracketis fixed, the cleanability of the multi-bracket is not satisfactory.

On the other hand, in the case of the expansion plate as a removableappliance, an expansion screw is provided between divided plates. Thescrew is turned to move the plates, which cooperate with a wire placedbetween tooth rows to move a correction target tooth row. However, theexpansion plate is partially fixed to teeth by wires. Therefore, smallpart of the plate is sustained in the oral cavity, so that the plate iseasily detached. Moreover, no satisfactory anchorage is provided for theexpansion plate. Therefore, the influence of the reaction force islikely to cause unintended movement of a tooth row adjacent to thecorrection target tooth row. Due to the structure of the expansionplate, the expansion plate only obliquely moves teeth, but difficultlyrealizes horizontal movement (parallel movement) of teeth. In the caseof conventional expansion plate, the expansion screw can only beprovided on the lingual side. However, even when the expansion screwcannot be provided on the lingual side due to, for example, aconsiderably narrow arch, the appliance of the present invention allowsthe expansion screw to be provided at any place, for example, on thelabial side. Therefore, the appliance of the present invention isapplicable to remarkably many cases as compared to the conventionaltypes. In the case of an aligner described, for example, in PatentDocument 1, a tooth row, gums, and cervical parts are covered alongtheir current shape to ensure a large anchorage. While the largeanchorage is ensured, a large force in a desired movement directionwhich is exerted on a correction target tooth row is obtained, therebyattempting to move the correction target tooth row in the desiredmovement direction. However, a portion of the aligner corresponding tothe correction target tooth row, differently from a portion of thealigner corresponding to other tooth rows, has a shape deviating fromthe current shape of the correction target tooth row in order to obtainforce to move the correction target tooth row in a desired movementdirection. It is difficult to place the aligner having such a shape inthe oral cavity without deforming portions of the aligner correspondingto the correction target tooth row and a tooth row adjacent to thecorrection target tooth row. Therefore, only a thin resin having athickness of about 0.2-0.8 mm can be used as the aligner, so thatpermanent deformation of the aligner may be easily caused. Thus, thealigner does not fit to the tooth row adjacent to the correction targettooth row, and a gap is formed between the aligner and the tooth row. Asa result, at the tooth row adjacent to the correction target tooth row,the anchorage by the aligner does not satisfactorily function, and thetooth row adjacent to the correction target tooth row are greatlyinfluenced by the reaction force of the force applied to the correctiontarget tooth row. Thus, unintended movement of the adjacent tooth row islikely to be caused. The aligner has to be changed a plurality of timesin order to correct tooth alignment while accordingly adjusting thedistance of movement of the tooth row with the shape of the aligneraccordingly stepped up. This increases the period and cost of treatment.

In view of the foregoing, it is an object of the present invention toprovide an orthodontic appliance capable of easily achieving andensuring not only buccal/lingual movement but also distal/mesialmovement of a correction target tooth while an anchorage issatisfactorily ensured, so that highly predictable treatment can beachieved in various cases. It is another object of the present inventionto provide an orthodontic appliance allowing horizontal movement andinclination of a correction target tooth by satisfactorily ensuring theanchorage. It is another object of the present invention to provide anorthodontic appliance which is easily used together with a skeletalanchor, and has high convenience and excellent aesthetic property.

Solution to the Problem

To achieve the objects, an example of the correction device according tothe present invention has the configuration as described below.

That is, a basic configuration of a correction device according to thepresent invention is a correction device configured to a move correctiontarget tooth of a patient in a desired direction. The correction deviceincludes a grip member formed to fit to an inner shape of the oralcavity of the patient so as to grip and cover a tooth row, and gum partsand alveolar bone parts on the buccal side and the lingual side of thetooth row of the patient. The grip member includes a first piece and asecond piece independent of the first piece, and further includes aforce applying member provided to connect the first piece to the secondpiece and configured to move the correction target tooth to the desireddirection.

With this basic configuration of the correction device, while at leastone of the first piece or the second piece which are independent of eachother and included in the grip member is used as a strong anchorage, thecorrection target tooth gripped by the grip member can be reliably movedin a desired direction by the force applying member. Since at least oneof the first piece or the second piece serves as a strong anchorage,teeth gripped as the anchorage is prevented from being moved by areaction of the force applied to the correction target tooth. The gripmember covers an area extending from the crown part to the periphery ofthe cervical part of a tooth gripped by the grip member. Therefore, theforce exerted by the force applying member is applied not only to thecrown portion of the correction target tooth but also the entire regionto the cervical part. Thus, the horizontal movement but not theinclination movement of the correction target tooth is easily performed.Since the area extending from the crown part to the periphery of thecervical part are covered, gripping force is strong, so that the gripmember is less likely to be displaced and detached leading to highefficiency of correction. As described above, with the correctiondevice, it is possible to easily achieve and ensure movement in adesired direction (not only the buccal/lingual movement but also thedistal/mesial movement) of the correction target tooth while theanchorage is satisfactorily ensured, so that highly predictabletreatment can be achieved.

In the basic configuration of the correction device, when the correctiondevice is used on an upper jaw side, the grip member may further includea palate portion continuous with the portion covering the alveolar bonepart on a lingual side of the tooth row and formed to fit to a shape ofthe palate.

With this configuration, the second piece on the upper jaw side servesas a more stable anchorage via the palate portion.

In a first configuration of the correction device, the first piece gripsthe correction target tooth to cover an area extending from a crown partto a periphery of a cervical part of a tooth row of the patient, and thesecond piece covers an area extending from a crown part to a peripheryof a cervical part of a tooth row of the patient.

In the first configuration of the correction device, the first pieceincluded in the grip member covers at least an area extending from thecrown part to the periphery of the cervical part of a correction targettooth so as to grip the correction target tooth, and the second pieceincluded in the grip member and independent of the first piece covers atleast an area extending from the crown part to the periphery of thecervical part of non-target teeth except the correction target tooth.With this configuration, the second piece serves as a strong anchorage.Therefore, by using the force applying member provided to connect thefirst piece to the second piece, the correction target tooth gripped bythe first piece can be moved in a desired direction. At this time, sincethe second piece serves as a strong anchorage, the non-target teethgripped by the second piece are prevented from being moved by reactionforce of the force applied to the correction target tooth gripped by thefirst piece. Since the second piece serves as a strong anchorage, usingthe force applying member allows the movement of the correction targettooth not only in a desired direction, i.e., in the buccal-lingualdirection but also in a distal direction and a mesial direction whichare conventionally difficult directions and also in upward and downwarddirections. Moreover, the first piece covers at least an area extendingfrom the crown part to the periphery of the cervical part of thecorrection target tooth. Therefore, the force by the force applyingmember is applied not only to the crown portion of the correction targettooth but also the entire region to the cervical part. Thus, thehorizontal movement but not the inclination movement of the correctiontarget tooth is easily performed. The correction target tooth is notmoved by using the property of the grip member itself while theanchorage is ensured. While the anchorage is ensured, the force applyingmember which is independent of the grip member including the first pieceand the second piece moves the correction target tooth. Therefore, it ispossible to ensure the movement of the correction target tooth in adesired direction. As described above, with the correction deviceaccording to the present invention, it is possible to easily achieve andensure not only the buccal/lingual movement but also the distal/mesialmovement of the correction target tooth while the anchorage issatisfactorily ensured, so that highly predictable treatment can beachieved.

The correction device covers the entire teeth and the large portion ofthe gum, so that the force applying member can be provided at anyposition of the correction device. Thus, the correction device isapplicable to many cases. Even when the correction device is changed dueto step up, a post-aligned tooth is used together with the existinganchorage so as to be a new anchorage, so that it is possible to set anew second piece serving as a more stable anchorage. With thisconfiguration, the new second piece can also serve as a retainer toprevent the post-aligned tooth from returning to its pre-alignmentposition.

In the correction device of the first configuration, a skeletal anchormay be implanted in the second piece.

Thus, a skeletal anchor such as a mini screw or an implant which servesas a definitive anchorage is implanted in the second piece, so that thesecond piece serves as a stable and definitive anchorage. This is veryeffective, in particular, when the entire tooth row including thealveolar bone of a patient is moved in the front, rear, left, and rightdirections, for example, in the buccal-lingual directions and in thedistal-mesial directions with respect to the cranial bone and thejawbone. Cases subjected to surgical orthodontics such as osteotomyinvolving high risks can be reduced as much as possible. In setbackmovement of the entire tooth row by a currently trialed method in whicha multi-bracket is used together with a skeletal anchor, force isobliquely exerted, so that three dimensional misalignment may be caused,and forward and lateral movement is currently impossible. However, inthe present correction device, no three dimensional misalignment iscaused, and the forward and lateral movement is also possible.

In a second configuration of the correction device, the first piece maygrip the correction target tooth to cover an area extending from a crownpart to a periphery of a cervical part of a tooth row of a patient, thesecond piece may grip a correction target tooth, which is different fromthe correction target tooth gripped by the first piece, to cover an areaextending from a crown part to a periphery of a cervical part of a toothrow of the patient, and when the correction device is used for a lowerjaw, the first piece and the second piece may extend to positions closeto front teeth, and the force applying member may be positioned near thefront teeth.

In the second configuration of the correction device, both of the firstpiece and the second piece of the grip member cover at least an areaextending from the crown part to the periphery of the cervical part of acorrection target tooth to grip the correction target tooth. With thisconfiguration, while the first piece and the second piece serve as astrong anchorage, the force applying member provided to connect thefirst piece to the first piece can be used to move the correction targettooth gripped by the first piece and the second piece in a desireddirection. Similarly to the first configuration, the first piece and thesecond piece serve as a strong anchorage also in the secondconfiguration. This prevents movement caused by reaction force of theforce applied to the gripped correction target tooth. Similarly to thefirst configuration, not only movement in the buccal-lingual directions,but also movement in the distal direction and the mesial direction, andalso the upward and downward directions which are conventionallydifficult directions are possible. Moreover, the horizontal movement butnot the inclination movement of the correction target tooth is easilyperformed. Movement of the correction tooth in a desired direction byusing the force applying member can be ensured. In particular, thisconfiguration is more suitable when a correction target tooth gripped bythe first piece and a correction target tooth gripped by the secondpiece are in a symmetric positional relationship.

In a third configuration of the correction device, the first piece gripsthe correction target tooth to cover an area extending from a crown partto a periphery of a cervical part of a tooth row of a patient, thesecond piece grips a correction target tooth, which is different fromthe correction target tooth gripped by the first piece, to cover an areaextending from a crown part to a periphery of a cervical part of a toothrow of the patient, and when the correction device is used for an upperjaw, the force applying member is provided on the palate portion.

With the third configuration of the correction device, advantagessimilar to those obtained by the second configuration used for the lowerjaw can be obtained. Similarly, the third configuration is more suitablewhen a correction target tooth gripped by the first piece and acorrection target tooth gripped by the second piece are in a symmetricpositional relationship.

The third configuration of the correction device may further include athird piece forming the grip member, formed independently of and nearthe first piece and the second piece, and covering an area extendingfrom the crown part to the periphery of the cervical part of a tooth rowof the patient, and a fixing member connected to the force applyingmember and extending from the force applying member to the third piece.

With this configuration, the third piece serves as a strong anchorage.Thus, using the strong anchorage, it is possible to more reliably movethe correction target teeth gripped by the first piece and the secondpiece in a desired direction.

In a fourth configuration of the correction device, the first piece maygrip the correction target tooth to cover an area extending from thecrown part to the periphery of the cervical part of a tooth row of thepatient, and a skeletal anchor may be implanted in the second piece.

Thus, a skeletal anchor such as a mini screw or an implant which servesas a definitive anchorage is implanted in the second piece, so that thesecond piece serves as a strong and definitive anchorage. This is veryeffective, in particular, when the entire tooth row including thealveolar bone of a patient is moved in the front, rear, left, and rightdirections, for example, in the buccal-lingual directions and in thedistal-mesial directions with respect to the cranial bone and thejawbone. Cases subjected surgical orthodontics such as osteotomyinvolving high risks can be reduced as much as possible. In setbackmovement of the entire tooth row by a currently trialed method in whicha multi-bracket is used together with a skeletal anchor, force isobliquely exerted, so that three dimensional misalignment may be caused,and forward and lateral movement is currently impossible. However, inthe present correction device, no three dimensional misalignment iscaused, and the forward and lateral movement is also possible.

In the correction device according to the present invention, the desireddirection is a distal or mesial direction, a lingual side or buccal sidedirection, or an upward or downward direction with respect to the toothrow.

In the correction device according to the present invention, when thereis a correction target tooth to be obliquely moved in the lingual sideor buccal side direction, a portion of the grip member covering thecrown part of the correction target tooth to be obliquely moved ispreferably removed on the buccal side or the lingual side.

As described above, the portion of the grip member covering the crownpart of the correction target tooth to be obliquely moved has beenpartially removed on the buccal side or on the lingual side. Therefore,force applied by the force applying member is not received by the entireregion from the crown portion to the cervical part, but the force isapplied in an oblique direction so that the tooth is inclined toward theside where the portion of the grip member at the crown has been removed.Thus, it is also possible to obliquely move the correction target tooth.

In the correction device according to the present invention, a wire, ascrew, a spring, an orthodontic rubber, or a magnet may be used as theforce applying member.

In the correction device according to the present invention, the screw,the spring, the orthodontic rubber, or the magnet may be provided toextend over the first piece and the second piece in a directioncorresponding to the moving direction.

In this case, the first piece and the second piece each has a portioninto which a screw, spring, orthodontic rubber, or a magnet isincorporated, and the portion is formed as a thick part.

In the correction device according to the present invention, it isaesthetically advantageous when the grip member is made of a transparentresin.

In the correction device according to the present invention, the gripmember preferably has a portion having a two-layer structure. Theportion having the two-layer structure includes a lower layer which is amembrane sheet made of silicon and an upper layer made of thetransparent resin.

With this configuration, the grip member can be used together with, forexample, a fixed-type multi-bracket. That is, when a wire is placed onthe entire tooth row by a button, the correction target tooth can bemoved as described above by the correction device with the multi-bracketcovered with the silicon membrane sheet which is the lower layer. Asdescribed above, the correction device can also be used as a rescuesystem of the multi-bracket. That is, orthodontic treatment providing asynergistic effect obtained by combining the advantage obtained by themulti-bracket with the advantage obtained by the correction device isalso possible. The structure is effective in the case of crowding in theoral cavity of a patient similarly to the case where a multi-bracket isused.

In the correction device according to the present invention, thetransparent resin may contain carbon.

With this configuration, the gripping force of the grip member can beenhanced, so that a more stable anchorage is ensured, and movement ofthe correction target tooth in a desired direction can be furtherensured. When the grip member made of a transparent resin is used as analigner, carbon is partially used such that a portion which ispreferably flexible and a portion which is preferably non-flexible areformed to have the same resin thickness. In this way, it is alsopossible to handle movement of a long tooth row depending on thecondition of the tooth row of a patient.

In the correction device according to the present invention, the gripmember may cover a region including the tooth row, the gum parts, andhighest contour portions of the alveolar bone part on the buccal side ofthe tooth row.

In the correction device according to the present invention, the gripmember may be configured to grip the entire tooth row of a patient.

With this configuration, all the teeth of a patient gripped by the gripmember can be moved in a desired direction by using the force applyingmember. That is, the entire tooth row inclusive of the alveolar boneparts of the patient can be moved in a desired directions to the front,rear, left, and right (e.g., buccal-lingual directions, distal-mesialdirections) with respect to the cranial bone and the jawbone. Therefore,bimaxillary protrusion, bimaxillary overgrowth and underdevelopment canbe treated, so that physical and aesthetic stress caused whenconventional facial masks or headgears are used can be significantlyreduced. In particular, in a conventional method, i.e., a facial mask ora headgear for moving the entire tooth row, the entire tooth row can bemoved in front and rear directions, but a tooth row displaced in theleft or right direction due to behavior, etc. cannot be moved to theright or left direction. The present correction device allows movementin right-left directions which is conventionally difficult. Moreover, inthe case of severe bimaxillary overgrowth/underdevelopment, the gripmember can be pulled or pushed in combination with an extraoralanchorage such as the facial mask and the headgear or an intramaxillaryanchorage, so that application of stronger force to move the entiretooth row is possible.

In the correction device according to the present invention, the firstpiece may be used for the upper jaw, and covers an area extending fromthe crown part to the periphery of the cervical part of the entire toothrow of the upper jaw of the patient, the second piece may be used forthe lower jaw, and covers an area extending from the crown part to theperiphery of the cervical part of the entire tooth row of the lower jawof the patient, and the force applying member may be an intermaxillaryrubber.

According to a fifth configuration of the correction device, when apatient has an overgrown or underdeveloped upper jaw and an overgrown orunderdeveloped lower jaw, and the tooth row of the upper jaw and thetooth row of the lower jaw are displaced with respect to each other, thedisplacement can be corrected by using, for example, the intermaxillaryrubber as a force applying member disposed at the first piece coveringan area extending from the crown part to the periphery of the cervicalpart of the entire tooth row of the upper jaw and the second piececovering a region from the crown part to a periphery of the cervicalpart of the entire tooth row of the lower jaw. In particular, when theupper jaw is overgrown, and the lower jaw is underdeveloped, or when theupper jaw is underdeveloped, and the lower jaw is overgrown, thedisplacement between the lower jaw and the upper jaw can be effectivelycorrected without using a skeletal anchor.

A skeletal anchor may be implanted in both or one of the first piece andthe second piece.

For example, when a skeletal anchor is implanted in a piece for theupper jaw, and no skeletal anchor is implanted in a piece for the lowerjaw, the upper jaw serves as an anchorage, and a tooth row of the lowerjaw can be primarily moved in an intended direction depending on thedirection in which the intermaxillary rubber is attached. In contrast,when no skeletal anchor is implanted in a piece for the upper jaw, and askeletal anchor is implanted in a piece for the lower jaw, the lower jawserves as an anchorage, and a tooth row of the upper jaw can be moved.When a skeletal anchor is implanted in a piece for each of the upper jawand the lower jaw, the intermaxillary rubber serves as a member applyingopposite forces. Thus, growth promotion/growth inhibition of the entirethe jawbone and the facial bone including the entire tooth row fixed bythe skeletal anchor is possible. Depending on the direction in which theintermaxillary rubber is attached, growth promotion/growth inhibition ofthe upper jawbone and the face bone around the upper jaw bone or growthpromotion/growth inhibition of the lower jawbone and the face bonearound the lower jaw bone is possible.

Advantages of the Invention

With the correction device according to the present invention, it ispossible to easily achieve and ensure not only the buccal/lingualmovement but also the distal/mesial movement of the correction targettooth while the anchorage is satisfactorily ensured, so that highlypredictable treatment can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1( a) and 1(b) are views illustrating an example structure of acorrection device according to an embodiment of the present invention,wherein FIG. 1( a) shows a correction device used on a lower jaw side,and FIG. 1( b) shows a correction device used on an upper jaw side.

FIGS. 2( a)-2(d) are cross sectional views illustrating various examplestructures of the correction device according to the embodiment of thepresent invention placed on a tooth row.

FIG. 3 is a view illustrating an example of a force applying member ofthe correction device according to the embodiment of the presentinvention.

FIGS. 4( a) and 4(b) are views illustrating steps in a method ofmanufacturing the correction device according to the embodiment of thepresent invention.

FIGS. 5( a) and 5(b) are views illustrating steps in the method ofmanufacturing the correction device according to the embodiment of thepresent invention.

FIGS. 6( a) and 6(b) are views illustrating a variation of the structureof the correction device according to the embodiment of the presentinvention, wherein a skeletal anchor is used, FIG. 6( a) shows acorrection device used on the lower jaw side, and FIG. 6( b) shows acorrection device used on the upper jaw side.

FIG. 7 is a view illustrating a variation of the structure of thecorrection device according to the embodiment of the present invention,wherein the entire tooth row is moved, and the correction device is usedon the upper jaw side.

FIGS. 8( a) and 8(b) are views illustrating a variation of the structureof the correction device according to the embodiment of the presentinvention, wherein the entire tooth row is moved using the skeletalanchor together with the correction device, FIG. 8( a) shows acorrection device used on the lower jaw side, and FIG. 8( b) shows acorrection device used on the upper jaw side.

FIGS. 9( a) and 9(b) are views illustrating a variation of the structureof the correction device according to the embodiment of the presentinvention, wherein a wire is used instead of a screw, FIG. 9( a) shows acorrection device for on the lower jaw side, and FIG. 9( b) shows acorrection device used on the upper jaw side.

FIGS. 10( a) and 10(b) are views illustrating a variation of thestructure of the correction device according to the embodiment of thepresent invention, wherein a region covering the outside of the toothrow is large, FIG. 10( a) shows a correction device used on the lowerjaw side, and FIG. 10( b) shows a correction device used on the upperjaw side.

FIGS. 11( a)-11(c) are views illustrating a variation of the structureof correction devices according to an embodiment of the presentinvention, wherein a first piece and a second piece are formed to havethe same size so that tooth rows facing each other are moved together tothe buccal side or the lingual side by applying opposite forces exertedby the force applying member. FIG. 11( a) shows a correction device usedon the lower jaw side, FIG. 11( b) shows a correction device used on theupper jaw side, and FIG. 11( c) shows a correction device in whichfixing members drawn out of the force applying member are provided atgrip members near the first piece and the second piece.

FIGS. 12( a) and 12(b) are photos showing examples of correction devicesaccording to an embodiment of the present invention, wherein FIG. 12( a)shows an example in which a row of two teeth from the back is moved by acorrection device used on the upper jaw, and FIG. 12( b) shows anexample in which the correction device used on the upper jaw side isdivided at the center thereof so that a first piece and a second pieceof a grip member are formed to have the same size, so that oppositeforces are applied to tooth rows facing each other by the force applyingmember, and tooth rows on the left and on the right are moved togetherby the same distance. In this case, a conventional expansion platecauses oblique movement, but the present invention allows horizontalmovement (parallel movement). At the same time, the present inventionalso allows compression of left and right tooth rows which wasdifficultly realized by removable-type appliances. The present inventionalso allows horizontal movement.

FIGS. 13( a)-13(c) are views illustrating a variation of the structureof the correction device according to an embodiment of the presentinvention, wherein the views each show an example structure in which agrip member is placed on each of the upper jaw side and the lower jawside, FIG. 13( a) shows an example in which lower jaw underdevelopmentor upper jaw overgrowth is corrected without using a skeletal anchor,FIG. 13( b) shows an example in which a skeletal anchor is implanted ina grip member on the upper jaw side to correct the lower jaw overgrowth,and FIG. 13( c) shows an example in which a skeletal anchor is implantedin the grip members on the upper jaw side and the lower jaw side tocorrect the lower jaw overgrowth or the upper jaw underdevelopment.

FIG. 14( a) is a cross sectional view illustrating an example structureof the correction device according to the embodiment of the presentinvention, wherein a correction target tooth is obliquely moved, andFIG. 14( b) is a cross-sectional view illustrating an example of thestructure of the correction device according to the embodiment of thepresent invention, wherein a grip member has a two-layer structureincluding a lower layer and an upper layer.

FIG. 15 is a cross-sectional view illustrating an example structure of avariation of a force applying member provided to connect a first pieceand a second piece of the correction device according to the embodimentof the present invention.

FIG. 16 is a cross-sectional view illustrating an example structure of avariation of the force applying member provided to connect the firstpiece and the second piece of the correction device according to theembodiment of the present invention.

FIG. 17 is a cross-sectional view illustrating an example structure of avariation of the force applying member provided to connect the firstpiece and the second piece of the correction device according to theembodiment of the present invention.

FIGS. 18( a)-18(d) are views illustrating case 1 in which a correctiondevice according to an embodiment of the present invention is used.

FIGS. 19( a)-19(d) are views illustrating case 2 in which a correctiondevice according to an embodiment of the present invention is used.

FIGS. 20( a)-20(d) are views illustrating case 3 in which a correctiondevice according to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

An embodiment of the present invention will be described below withreference to the drawings.

FIGS. 1( a) and 1(b) are views illustrating an example structure of acorrection device according to an embodiment of the present invention,wherein FIG. 1( a) shows a correction device used on a lower jaw side,and FIG. 1( b) shows a correction device used on an upper jaw side.

As illustrated in FIG. 1( a), a correction device 100 according to thepresent embodiment includes a grip member which is configured to be usedboth on the upper jaw side and on the lower jaw side, is made of, forexample, a resin material to fit to an inner shape of the oral cavity ofa patient so as to grip and cover a tooth row, gum parts, and alveolarbone parts of the patient, and includes a first piece 20 and a secondpiece 10. Specifically, the grip member covers a tooth row, and gumparts and alveolar bone parts on a buccal side and a lingual side of thetooth row. The first piece 20 included in the grip member covers atleast an area extending from the crown part to the periphery of thecervical part of a tooth misalignment of which is to be corrected(correction target tooth) so as to grip the correction target tooth. Thesecond piece 10 included in the grip member is part of the grip memberexcept the first piece 20 and is formed as a piece independent of thefirst piece 20. A force applying member 30 is provided to connect thefirst piece 20 to the second piece 10. The force applying member 30moves the correction target tooth in a desired direction. Here, forexample, a wire, a screw, a spring, a rubber, or a magnet can be used asthe force applying member 30. FIG. 1( a) illustrates an example in whicha gap is formed between a back tooth located at an innermost position inthe oral cavity and a tooth adjacent to the back tooth, and a tooth rowcovered with the first piece 20 is moved in a direction toward the backtooth by using, for example, an expansion or contraction screw as theforce applying member 30, wherein the screw is placed on the first piece20 and the second piece 30 to extend over the first piece 20 and thesecond piece 10. In this example, expanding the screw allows the toothrow covered with the first piece 20 to move in a direction toward theback tooth. Portions of the first piece 20 and the second piece 10 onwhich the force applying member 30 is provided have an increasedthickness by the force applying member 30, and the portions having theincreased thickness are thick portions 22(see, for example, FIG. 2).

As illustrated in FIG. 1( b), when the correction device 100 accordingto the present embodiment is used on the upper jaw side, the secondpiece 10 preferably further includes a palate portion 15 continuous witha portion covering the alveolar bone part located on the lingual side ofthe tooth row and formed to fit to the shape of the palate. Note thatthe example in which a tooth row covered with the first piece 20 ismoved is similar to that described with reference to FIG. 1( a).

Next, FIGS. 2( a)-2(d) are cross-sectional views illustrating variousexample structures of the correction device 100 according to theembodiment of the present invention, wherein in the cross-sectionalview, the first pieces 20 of FIG. 1( b) are taken along a direction fromthe buccal side to the lingual side of the tooth row, and a portionincluding the force applying member 30 connecting the first piece 20 tothe second piece 10 is shown.

As illustrated in FIG. 2( a), the first piece 20 covers a tooth rowincluding a correction target tooth 50 and a region at least an areaextending from a crown part a on both of the buccal side (on the left inthe plane of the paper) and the lingual side (on the right in the planeof the paper) of the tooth row to a peripheral portion of the cervicalpart b to fit to the shapes of the crown part a and the peripheralportion of the cervical part b. The second piece 10 covers a tooth rowof non-target teeth (not shown) and at least an area extending from acrown part a on both of the buccal side (on the left in the plane of thepaper) and the lingual side (on the right in the plane of the paper) tothe cervical part b of the tooth row. At the portion of the correctiontarget tooth 50 in FIG. 2( a), the second piece 10 covers at least anarea extending from the periphery of the cervical part b on the lingualside of the tooth row of the correction target tooth 50 to the alveolarbone part d. FIG. 2( a) shows the correction device used on the upperjaw side, and thus the second piece 10 continuously covers the palateportion. The first piece 20 may also cover a relatively large area froma gum part c to an alveolar bone part d on the buccal side (on the leftin the plane of the paper) of the correction target tooth 50 (see forexample, FIG. 10). In order to connect the first piece 20 to the secondpiece 10, the force applying member 30 is provided along a direction inwhich the teeth are aligned (i.e., distal direction or mesial direction)in FIG. 2( a). Thus, expansion or contraction of, for example, the screwas the force applying member 30 is caused to move the correction targettooth 50 gripped by the first piece 20 in the distal direction or themesial direction (in a direction perpendicular to the plane of the paperor in a direction away from the plane of the paper).

FIG. 2( b) shows an example in which the force applying member 30 isprovided at a position different from the position shown in FIG. 2( a).The force applying member 30 is provided on a lingual side portion ofthe correction target tooth 50 in a lingual side-buccal side directionof the tooth row. Thus, expansion or contraction of, for example, thescrew as the force applying member 30 is caused to move the correctiontarget tooth 50 gripped by the first piece 20 in a buccal side directionor a lingual side direction.

FIG. 2( c) shows an example in which the force applying member 30 isprovided at a position different from the positions shown in FIGS. 2( a)and 2(b). The force applying member 30 is provided on the lingual sideportion of the correction target tooth 50 in a lower side-upper sidedirection (a direction from the lower jaw toward the upper jaw) of thetooth row. Thus, expansion or contraction of, for example, the screw asthe force applying member 30 is caused to move the correction targettooth 50 gripped by the first piece 20 in the upper side direction or inthe lower side direction. As described above, when for example, a screw,a spring, an orthodontic rubber, or a magnet is used, the force applyingmember 30 is provided to extend over the first piece 20 and the secondpiece 10 in a direction corresponding to an intended moving direction,so that it is possible to move the correction target tooth 50 in thedirection in which the force applying member 30 is provided.

As illustrated in FIG. 2( d), projecting members 60 such as squarebuttons are provided to the configuration of FIG. 2( c) on the buccalside portion and the lingual side portion of the crown part a. Thisconfiguration ensures that the first piece 20 covering the correctiontarget tooth 50 is not detached when the correction target tooth 50 ismoved in the upper side direction.

Here, the force applying member 30 may be, as described above, forexample, a screw, a spring, an orthodontic rubber, or a magnet, whereina screw 30S illustrated in FIG. 3 can be used as an example of thescrew. As illustrated in FIG. 3, the screw 30S is disposed to connectthe first piece 20 to the second piece 10. A pin 35 b is inserted into ahole 35 a formed at the center of the screw 30S, and the pin 35 b isturned in a direction indicated by the arrow or in a direction oppositeto the arrow, thereby the first piece 20 and the second piece 10 aremoved to be away from each other or to be close to each other. In thisway, for example, a correction target tooth gripped by the first piece20 (note that the second piece 10 may grip a correction target tooth asdescribed later) can be moved in a desired direction. The screwillustrated in FIG. 3 is a general screw similar to a screw generallyused for an expansion plate.

Next, FIGS. 4( a) and 4(b) and FIGS. 5( a) and 5(b) sequentiallyillustrate example steps in a method of manufacturing the correctiondevice according to the present embodiment.

First, as illustrated in FIG. 4( a), a model 200 having a reconstructedshape of the oral cavity of a patient is prepared by a known method.Here, as illustrated in the figure, an example in which a gap is formedbetween a back tooth located at an innermost position in the oral cavityand a tooth adjacent to the back tooth is shown. Next, as illustrated inFIG. 4( b), a grip member 100A is formed of, for example, a resinmaterial to have a shape fitting to the model. That is, the grip member100A is formed to fit to an inner shape of the oral cavity of a patientso as to grip and cover a tooth row, gum parts, and alveolar bone partsof the patient. Specifically, the grip member 100A covers the tooth row,the gum parts and the alveolar bone parts on the buccal side and thelingual side of the tooth row (note that as described above, it issufficient that the grip member 100A covers at least an area extendingfrom the crown part to the periphery of the cervical part).

Next, as illustrated in FIG. 5( a), the grip member 100A is cut into afirst piece 20 and a second piece 10 which are separated and independentof each other. Specifically, the grip member 100A is divided into thefirst piece 20 which grips and covers at least an area extending fromthe crown part to the cervical part of the correction target tooth 50and the second piece 10 which grips and covers at least an areaextending from the crown part to the periphery of the cervical part ofthe non-target tooth.

Then, as illustrated in FIG. 5( b), a force applying member 30 whichmoves the correction target tooth 50 in a desired direction is providedon the first piece 20 and the second piece 10 to connect the first piece20 to the second piece 10. The force applying member 30 is provided, sothat portions of the first piece 20 and the second piece 10 on which theforce applying member 30 is provided have a greater thickness than theother portions the first piece 20 and the second piece 10, and theportions having the greater thickness are thick portions 22. Thus, thecorrection device 100 according to the present embodiment is formed.

In the above-described embodiment, the grip member including the firstpiece 20 and the second piece 10 can be made of, for example, a resinmaterial having a thickness of 0.2 mm-0.8 mm. When the grip member hassuch a thickness, patients feels as little discomfort as when knownaligners are used. In the case of known aligners, as described in thetechnical problem, permanent deformation may be caused, and the alignersmay not satisfactorily function as an anchorage due to the permanentdeformation. However, the grip member according to the presentembodiment is divided into the first piece 20 and the second piece 10,so that no permanent deformation is caused as in the case of the knownaligners, and the grip member can satisfactorily function as ananchorage. On the other hand, the grip member including the first piece20 and the second piece 10 can be made of, for example, a resin materialhaving a thickness greater than or equal to 2 mm. Also in this case,permanent deformation is not caused, and the grip member can more stablyfunction as an anchorage and can be used as an aligner.

The correction device 100 according to the present embodiment having theconfiguration described above provides the following advantages. Thatis, the first piece 20 included in the grip member covers at least anarea extending from the crown part to the periphery of the cervical partof the correction target tooth 50 to grip the correction target tooth50, and the second piece 10 included in the grip member and independentof the first piece 20 covers and grips at least an area extending fromthe crown part to the periphery of a cervical part of the non-targetteeth except the correction target tooth 50. With this configuration,the second piece 10 serves as a strong anchorage. Therefore, by usingthe force applying member 30 provided to connect the first piece 20 tothe second piece 10, the correction target tooth 50 gripped by the firstpiece 20 can be moved in a desired direction. At this time, since thesecond piece 10 serves as a strong anchorage, the non-target teethgripped by the second piece 10 are prevented from being moved byreaction force of the force applied to the correction target tooth 50gripped by the first piece 20. Since the second piece 10 serves as astrong anchorage, providing the force applying member 30 at a suitableposition allows the movement of the correction target tooth 50 not onlyin a desired direction, i.e., in the buccal-lingual direction but alsoin a distal direction and a mesial direction which are conventionallydifficult directions and also in upward and downward directions.Moreover, the first piece 20 covers at least an area extending from thecrown part to the periphery of the cervical part of the correctiontarget tooth 50. Therefore, the force by the force applying member 30 isapplied to not only the crown portion of the correction target tooth 50but also the entire region to the cervical part. Thus, the horizontalmovement but not the inclination movement of the correction target tooth50 is easily performed. The correction target tooth 50 is not moved byusing the property of the grip member itself while the anchorage isensured. While the anchorage is ensured, the force applying member 30which is independent of the grip member including the first piece 20 andthe second piece 10 moves the correction target tooth 50. Therefore, itis possible to ensure the movement of the correction target tooth 50 ina desired direction. Therefore, with the correction device 100 accordingto the present embodiment, it is possible to easily achieve and ensurenot only the buccal/lingual movement but also the distal/mesial movementof the correction target tooth 50 while the anchorage is satisfactorilyensured, so that highly predictable treatment can be achieved. When thecorrection device 100 according to the present embodiment is used on theupper jaw side, the second piece 10 has the palate portion 15. Thepalate portion 15 is continuous with a part covering the alveolar bonepart located on the lingual side of the tooth row, and is formed to fitto the shape of the palate, so that more stable anchorage can beensured. Even when the correction device 100 is changed due to step up,a post-aligned tooth is used together with an existing anchorage so asto be a new anchorage, so that it is possible to set a new second piece10 serving as a more stable anchorage. With this configuration, the newsecond piece 10 can also serve as a retainer to prevent the post-alignedtooth from returning to its pre-alignment position.

Next, variations of the correction device 100 according to the presentembodiment will be described.

FIGS. 6( a) and 6(b) illustrate variations of the correction device 100according to the embodiment of the present invention. Specifically, anexample structure is shown in which a skeletal anchor 70 is furtherprovided in the structure of the correction device 100 illustrated inFIGS. 1( a) and 1(b). FIG. 6( a) shows the correction device 100 used onthe lower jaw side, and FIG. 6( b) shows the correction device 100 usedon the upper jaw side.

As illustrated in FIGS. 5( a) and 5(b), the correction device 100according to the present embodiment can be used in a form in which theskeletal anchor 70 is implanted in the second piece 10 at the peripheryof the back teeth. The skeletal anchor 70 is, for example, a mini screwor an implant passing through the second piece 10.

Thus, the mini screw or the implant which serves as a definitiveanchorage is implanted in the second piece 10, so that the second piece10 serves as a stable and definitive anchorage. Thus, the correctiontarget tooth 50 gripped by the first piece 20 can be more reliably movedin a desired direction. Cases subjected surgical orthodontics such asosteotomy involving high risks can be reduced as much as possible. Theskeletal anchor 70 can be in a variety of shapes, but a square shapewhich is barely rotated by applied force, as illustrated in the figure,is preferable so that the skeletal anchor 70 serves as more stableanchorage.

FIG. 7 illustrates a variation of the structure of the correction device100 according to the embodiment of the present invention. Specifically,an example structure of the correction device 100 according to thepresent embodiment for moving the entire tooth row is illustrated,wherein the correction device 100 is used on the upper jaw side.

As illustrated in FIG. 7, the first piece 20 covers the entire row ofthe correction target tooth 50, whereas the second piece 10 does notcover the tooth row itself. In this case, in order to move the entiretooth row by the force applying member 30, for example, the first piece20 covers the entire tooth row, and the second piece 10 covers portionsother than those covered with the first piece 20. Specifically, thesecond piece 10 covers an area extending from the periphery of acervical part to a gum portion, and a peripheral region of an alveolarbone of a peripheral region of back teeth of the grip member (aperipheral region of the back teeth on the lingual side of the gripmember). The force applying member 30 is provided to extend over aportion of the first piece 20 corresponding to a region in the peripheryof a cervical part to a gum portion, a peripheral region of an alveolarbone of a peripheral region of back teeth and a portion of the secondpiece 10 corresponding to a region in the periphery of a cervical partto a gum portion, and a peripheral region of an alveolar bone of aperipheral region of back teeth adjacent to the portion of the firstpiece 20. With this configuration, the entire tooth row gripped by thefirst piece 20 can be moved in mesial-distal directions. Placing theforce applying member 30 at a suitable position allows the entire toothrow to move not only in mesial-distal directions but also in left-rightdirections. As described above, in the correction device 100 accordingto the present embodiment, the second piece 10 is used as anchorage, sothat all the teeth gripped by the first piece 20 can be moved in adesired direction by using the force applying member 30. That is, theentire tooth row inclusive of the alveolar bone of a patient can bemoved in desired directions to the front, rear, left, and right (e.g.,buccal-lingual directions, distal-mesial directions) with respect to thecranial bone and the jawbone. Therefore, bimaxillary protrusion,bimaxillary overgrowth and underdevelopment can be treated, so thatphysical and aesthetic stress caused when conventional facial masks orheadgears are used can be significantly reduced. In particular, in aconventional method, i.e., a facial mask or a headgear for moving theentire tooth row, the entire tooth row can be moved in mesial-distaldirections, but a tooth row displaced in the left or right direction dueto behavior, etc. cannot be moved to the right or left direction. Thecorrection device 100 according to the present embodiment allowsmovement in right-left directions which is conventionally difficult.

FIGS. 8( a) and 8(b) illustrate a variation of the structure of thecorrection device 100 according to the embodiment of the presentinvention. Specifically, an example structure is shown in which askeletal anchor 70 is further provided in the structure of thecorrection device 100 illustrated in FIG. 7. FIG. 8( a) shows thecorrection device 100 used on the lower jaw side, and FIG. 8( b) showsthe correction device 100 used on the upper jaw side.

As illustrated in FIGS. 8( a) and 8(b), the correction device 100according to the present embodiment can be used in a form in which theskeletal anchor 70 is implanted in the second piece 10. The skeletalanchor 70 is, for example, a mini screw or an implant passing throughthe second piece 10. The skeletal anchor 70 is preferably implanted at aportion of the second piece 10, for example, in the case of FIG. 8( a),a portion in the periphery of back teeth of the buccal side portion ofthe grip member, and for example, in the case of FIG. 8( b), a portionin the periphery of back teeth of the lingual side portion of the gripmember. In the example of FIG. 8( a), a structure in which the secondpiece 10, the force applying member 30, and the skeletal anchor 70 areformed at the back teeth on one side is illustrated in the figure, asimilar structure (not shown) is also formed at the back teeth on theother side.

Thus, the mini screw or the implant which serves as a definitiveanchorage is implanted in the second piece 10 (including the palateportion 15), so that the second piece 10 serves as a stable anddefinitive anchorage. Thus, it is possible to ensure the movement of theentire tooth row gripped by the first piece 20 in the left-rightdirections and in the distal-mesial directions with respect to thecranial bone and the jawbone. Cases subjected surgical orthodontics suchas osteotomy involving high risks can be reduced as much as possible. Insetback movement of the entire tooth row by a currently trialed methodin which a multi-bracket is used together with a skeletal anchor, forceis obliquely exerted, so that three dimensional misalignment may becaused, and forward and lateral movement is currently impossible.However, in the correction device 100 according to the presentembodiment, no three dimensional misalignment is caused, and the forwardand lateral movement is also possible.

FIGS. 9( a) and 9(b) illustrate a variation of the structure of thecorrection device 100 according to the embodiment of the presentinvention. Specifically, an example structure is illustrated in whichinstead of the screw as the force applying member 30 of the correctiondevice 100 illustrated in, for example, FIGS. 1( a) and 1(b), a wire 90serving as a force applying member is used, wherein FIG. 9( a) shows thecorrection device 100 used on the lower jaw side, and FIG. 9( b) showsthe correction device 100 used on the upper jaw side.

As illustrated in FIGS. 9( a) and 9(b), the wire 90 covers the firstpiece 20 and the second piece 10. The wire 90 is attached to the firstpiece 20 by, for example, an adhesive 80. The shape of the wire 90 isadjusted in advance so that force using return force is exerted on thecorrection target tooth 50 gripped by the first piece 20 moves in adesired direction in which the correction target tooth 50 is to bemoved. With this configuration, even with the correction device 100using the wire 90 as in the present embodiment, the second piece 10serves as a strong anchorage, so that advantages similar to thosedescribed above can be obtained by using the returning force of the wire90.

FIGS. 10( a) and 10(b) illustrate a variation of the structure of thecorrection device 100 according to the embodiment of the presentinvention. Specifically, an example structure is illustrated in which aregion of the second piece 10 covering the outside of the tooth row islarge as compared to that of the second piece 10 of the correctiondevice 100 illustrated in, for example, FIGS. 1( a) and 1(b), whereinFIG. 10( a) shows the correction device 100 used on the lower jaw side,and FIG. 10( b) shows the correction device 100 used on the upper jawside.

As illustrated in each of the figures such as FIGS. 1( a) and 1(b), whenthe grip member including the first piece 20 and the second piece 10 ofthe correction device 100 according to the present embodiment covers, onthe buccal side of the tooth row, at least an area extending from thecrown part to the periphery of the cervical part, more specifically, thetooth row, the gum part, and highest contour portions of the alveolarbone part, it is possible to obtain a strong anchorage as describedabove. However, as illustrated in FIGS. 10( a) and 10(b), the gripmember including the first piece 20 and the second piece 10 of thecorrection device 100 may also cover, on the buccal side of the toothrow, a lower portion of the alveolar bone part so that the force of thegrip member as the anchorage is further enhanced as compared to the gripmember of the correction device 100 illustrated in, for example, FIGS.1( a) and 1(b). In this case, placing the correction device 100 may bedifficult or cause pain depending on the oral shape of a patient.Therefore, the downward length of the grip member may be accordinglyadjusted. The present variation is applicable to any of the correctiondevices described above.

FIGS. 11( a)-11(c) illustrate variations of the structure of thecorrection device 100 according to an embodiment of the presentembodiment. Specifically, a first piece and a second piece are formed tohave the same size so that tooth rows facing each other are movedtogether to the buccal side or the lingual side by applying oppositeforces exerted by the force applying member, wherein FIG. 11( a) shows acorrection device 100 used on the lower jaw side, FIG. 11( b) shows acorrection device 100 used on the upper jaw side, and FIG. 11( c) showsa correction device 100 in which fixing members drawn out of the forceapplying member is provided on the grip member close thereto.

In FIG. 11( a), a first piece 11A grips, for example, four teeth fromthe back on one side as correction target teeth to cover an areaextending from the crown part to the periphery of the cervical part ofthe tooth row of a patient. The second piece 11B grips, for example,four teeth from the back on the other side as correction target teeth tocover a region from a crown part to a periphery of a cervical part ofthe tooth row of the patient. The correction device 100 is used for thelower jaw. Therefore, the first piece 11A and the second piece 11Bextend to a position near front teeth. The force applying member 30 isarranged at a position near the front teeth.

In FIG. 11( b), a first piece 11A grips correction target teeth to coveran area extending from the crown part to the periphery of the cervicalpart of the tooth row of a patient. The second piece 11B gripscorrection target teeth different from the above-described correctiontarget tooth to cover an area extending from the crown part to theperiphery of the cervical part of the tooth row of the patient. Thecorrection device is used for the upper jaw. Therefore, the forceapplying member 30 is provided at a palate portion.

In the configuration of each of FIGS. 11( a)-11(c), both of the firstpiece 11A and the second piece 11B of the grip member covers an areaextending from the crown part to the periphery of the cervical part ofthe correction target tooth to grip the correction target teeth.Therefore, while the first piece 11A and the second piece 11B are usedas strong anchorages, the correction target teeth gripped by the firstpiece 11A and the second piece 11B can be moved in a desired directionby using opposite forces exerted by the force applying member. Moreover,both of the first piece 11A and the second piece 11B are stronganchorages, which prevents movement caused by reaction force of theforce applied to the gripped correction target teeth. The correctiontarget teeth are easily moves not obliquely but horizontally. Thecorrection target teeth can be reliably moved in a desired direction byusing the force applying member. In particular, the present embodimentis more suitable when the correction target teeth gripped by the firstpiece 11A and the correction target teeth gripped by the second piece11B are symmetrical positional relationship. However, the presentinvention is not limited to the present embodiment, and similarcorrection is possible by accordingly modifying the design of the gripmember.

In the configuration of FIG. 11( c) which shows a configurationbasically similar to that shown in FIG. 11( b), but when a small numberof teeth gripped by the first piece 11A and the second piece 11B, athird piece 11C and a fourth piece 11D independent of the first piece11A and the second piece 11B are provided near the first piece 11A andthe second piece 11B. The force applying member 30 includes fixingmembers 35 extending from the force applying member 30 to the thirdpiece 11C and the fourth piece 11D. That is, each fixing member 35extends from a region extending over the first piece 11A and the secondpiece 11B to a corresponding one of the third piece 11C and the fourthpiece 11D. With this configuration, a stronger anchorage can beobtained.

Here, FIGS. 12( a) and 12(b) show examples of the correction device 100according to an embodiment of the present embodiment. FIG. 12( a) showsan example of a correction device similar to a correction deviceillustrated in FIGS. 18( b) and 18(c) relating to case 1 which will bedescribed later, wherein two teeth from the back are moved by using acorrection device used on the upper jaw side. FIG. 12( b) shows anexample of a correction device similar to that of FIG. 11( b), whereinFIG. 12( b) shows an example in which the correction device used on theupper jaw side is divided at the center thereof so that a first pieceand a second piece of a grip member are formed to have the same size, sothat opposite forces are applied to tooth rows facing each other by theforce applying member, and tooth rows on the left and on the right aremoved together by the same distance. In this case, a conventionalexpansion plate causes oblique movement, but the present inventionallows horizontal movement. At the same time, the present invention alsoallows compression of left and right tooth rows which was difficultlyrealized by removable-type appliances. The present invention also allowshorizontal movement. Note that FIG. 12( b) shows an example in which awire is attached to also correct the peripheral portion of front teeth.

FIGS. 13( a)-13(c) illustrate variations of the structure of acorrection device according to an embodiment of the present embodiment.Specifically, an example of the structure in which a grip member isplaced on each of the upper jaw side and the lower jaw side isillustrated.

FIG. 13( a) shows an example in which lower jaw underdevelopment orupper jaw overgrowth is corrected without using a skeletal anchor. Asillustrated in the figure, a first piece 300A which is the grip memberdescribed above is used for the upper jaw, and covers an area extendingfrom the crown part to the periphery of the cervical part of the entiretooth row of the upper jaw of a patient. Similarly, a second piece 300Bwhich is the grip member is used for the lower jaw, and covers a regionfrom a crown part to a periphery of a cervical part of the entire toothrow of the lower jaw of the patient. The first piece 300A and the secondpiece 300B are connected to each other by an intermaxillary rubber 400serving as the force applying member 30. Note that the intermaxillaryrubber 400 may be attached to projections, which have for example, abutton shape and are provided on the first piece 300A and the secondpiece 300B.

With this configuration, when the upper jaw is overgrown, the lower jawis underdeveloped, and the tooth row of the upper jaw and the tooth rowof the lower jaw are not in alignment with each other, theintermaxillary rubber 400 is accordingly used to apply stronger force tothe upper jaw side than to the lower jaw side, thereby pulling the upperjaw in the arrow direction in the figure to the right in the plane ofthe paper, so that the misalignment due to projection of the upper jawcan be easily corrected.

As illustrated in FIG. 13( b), a skeletal anchor 70 is implanted in thegrip member on the upper jaw side. Therefore, when the lower jaw isovergrown and the tooth row of the upper jaw and the tooth row of thelower jaw are not in alignment with each other, the lower jaw is movedby being pulled in the arrow direction in the figure by appropriatelyusing the intermaxillary rubber 400 with the upper jaw serving as ananchorage, so that the misalignment due to projection of the lower jawcan be easily corrected.

Although not illustrated in FIG. 13( b), the skeletal anchor 70 can beimplanted only in the grip member on the lower jaw side. For example,when the upper jaw which is anatomically instable is to be moved, inparticular, when the upper jaw is underdeveloped, the upper jaw can bemoved by being pulled out with the lower jaw serving as an anchorage.

In FIG. 13( c), skeletal anchors 70 are implanted in grip members on theupper jaw side and the lower jaw side. Thus, the intermaxillary rubber400 serves as a member applying opposite forces, and growthpromotion/growth inhibition of the entire the jawbone and the facialbone including the entire tooth row fixed by the skeletal anchors 70 ispossible. Depending on the direction in which the intermaxillary rubberis attached, growth promotion/growth inhibition of the upper jawbone andthe face bone around the upper jaw bone or growth promotion/growthinhibition of the lower jawbone and the face bone around the lower jawbone is possible. In FIG. 13( c), stronger force is applied to the upperjaw side than to the lower jaw side, thereby performing the growthinhibition of the lower jawbone and the facial bone near the lowerjawbone in the arrow direction in the figure to the left in the plane ofthe paper.

As described above, when a patient has an overgrown or underdevelopedupper jaw, an overgrown or underdeveloped lower jaw, and the tooth rowof the upper jaw and the tooth row of the lower jaw are not in alignmentwith each other, the misalignment can be easily corrected by using, forexample, an intermaxillary rubber as a force applying member. Inparticular, when the upper jaw is overgrown and the lower jaw isunderdeveloped, or when the upper jaw is underdeveloped and the lowerjaw is overgrown, the misalignment between the upper jaw and the lowerjaw can be effectively corrected without using the skeletal anchor, andwhen the skeletal anchor is used, growth promotion/growth inhibition ofthe entire the jawbone and the facial bone including the entire toothrow is possible.

FIG. 14( a) illustrates an example structure when a correction targettooth is obliquely moved by the correction device 100 according to theembodiment of the present invention.

As illustrated in FIG. 14( a), in the case where a correction targettooth 50 itself is inclined from the vertical direction, if thecorrection target tooth 50 is moved by, for example, the correctiondevice 100 illustrated in FIG. 2( b), the correction target tooth 50horizontally moves with the correction target tooth 50 being inclined.Therefore, when the correction target tooth 50 itself is inclined fromthe vertical direction as illustrated in FIG. 14( a), a first piece 20Ais preferably used in order to move the correction target tooth 50 inthe vertical direction. The first piece 20A has such a shape that anouter portion 20B corresponding to a crown part of the tooth row is, forexample, removed, or is not formed. With this configuration, thegripping force applied to the correction target tooth 50 by the firstpiece 20A is weak at the outer portion of the correction target tooth50. Therefore, the correction target tooth 50 inclined to the right fromthe vertical direction can be inclined leftward so that the correctiontarget tooth 50 stands along the vertical direction.

FIG. 14( b) illustrates an example structure in which the grip member ofthe correction device 100 according to the embodiment of the presentinvention has a two-layer structure including a lower layer and an upperlayer.

As illustrated in FIG. 14( b), when for example, a fixed-typemulti-bracket is placed on a tooth row, the grip member preferablyincludes a lower layer (a lower layer 20D of a first member 20, a lowerlayer 10D of a second member 10) made of a silicon membrane sheet and anupper layer (a upper layer 20C of a first member 20, a upper layer 20Dof a second member 10) made of a resin.

With this configuration, the grip member can be used together with, forexample, a fixed-type multi-bracket. That is, when a wire is placed onthe entire tooth row by, for example, a button 95, the correction targettooth 50 can be moved as described above by the correction device 100with the multi-bracket covered with the silicon membrane sheets 20D, 10Dwhich are lower layers (that is, correction by using the multi-bracketis continued). As described above, the correction device 100 can also beused as a rescue system of the multi-bracket. That is, orthodontictreatment providing a synergistic effect obtained by combining theadvantage obtained by the multi-bracket with the advantage obtained bythe correction device 100 is also possible. The structure in which thegrip member includes two layers, i.e., the lower layer and the upperlayer is effective, in particular, in the case of crowding in the oralcavity of a patient similarly to the case where a multi-bracket is used.

FIG. 15 illustrates an example structure of a variation of the forceapplying member 30 provided to connect the first piece 20 to the secondpiece 10 of the correction device 100 according to the embodiment of thepresent invention.

As illustrated in FIG. 15, the correction device 100 according to thepresent embodiment uses a screw 30A serving as a force applying member.The screw 30A includes for example, a main screw part 33 made of a knownset screw, a screw receiving part 32 through which the main screw part33 can pass, and a support member 31 placed on the second piece 10 andsupporting the screw receiving part 32. When the main screw part 33 isturned, the main screw part 33 advances toward the screw receiving part32 to press the first piece 20, or when the main screw part 33 isreversely turned, the screw part 33 moves away from the screw receivingpart 32. In this way, the correction target tooth 50 can be moved in thebuccal side direction or the lingual side direction. Thus, by using thescrew 30A having such a special structure, a force applying member 30which reduces discomfort of a patient can be realized even in a space ofthe narrow oral cavity.

FIG. 16 illustrates an example structure of a variation of the forceapplying member 30 provided to connect the first piece 20 to the secondpiece 10 of the correction device 100 according to the embodiment of thepresent invention.

As illustrated in FIG. 16, the correction device 100 according to thepresent embodiment uses a screw 30B serving as a force applying member.The screw 30B includes for example, a main screw part 211 made of aknown set screw, a relay member 210 formed continuously with the mainscrew part 211 and having no screw function, and a screw receiving part212 which is formed to match the shape of the relay member 210 in afemale-male relationship. The main screw part 33 is turned so that themain screw part 33 advances toward the screw receiving part 32, therebypressing the screw receiving part 212 via the relay member 210 to movethe correction target tooth 50 in the buccal side direction or thelingual side direction. At this time, the relay member 210 itselfpresses the screw receiving part 212 while the relay member 210 is idlyturned. Alternatively, the main screw part 33 is reversely turned sothat the main screw part 33 advances in a direction away from the screwreceiving part 32, and the screw receiving part 212 is pulled via therelay member 210 toward the main screw part 33. In this way, thecorrection target tooth 50 can be moved in the buccal side direction orthe lingual side direction. Thus, by using the screw 30B having such aspecial structure, a force applying member 30 which reduces discomfortof a patient can be realized even in a space of the narrow oral cavity.

FIG. 17 illustrates an example structure of a variation of the forceapplying member 30 provided to connect the first piece 20 with thesecond piece 10 of the correction device 100 according to the embodimentof the present invention.

As illustrated in FIG. 17, the correction device 100 according to thepresent embodiment uses a screw 30C serving as a force applying member.The screw 30C includes for example, a first magnet part 214 having aknown set screw form, and a second magnet part 213 provided at aposition facing the first magnet part 214. The first magnet part 214 isimplanted in the second piece 10, and the second magnet part 213 isimplanted in the first piece 20. The first magnet part 214 having theset screw shape is turned to move the first magnet part 214 in adirection toward the second magnet 213 or in a direction away from thesecond magnet 213. At this time, the positive magnetic poles and thenegative magnetic poles of the first magnet part 214 and the secondmagnet part 213 are arranged as illustrated in for example, in aconceptual view of the figure. In this way, the attracting force orrepelling force of the magnets can move the correction target tooth 50in the buccal side direction or the lingual side direction. Thus, byusing the screw 30C having such a special structure, a force applyingmember 30 which reduces discomfort of a patient can be realized even ina space of the narrow oral cavity. A configuration in which the secondmagnet part 213 is provided so as to be inclined from the verticaldirection to the buccal direction or the lingual direction, and thefirst magnet part 214 is implanted in the second piece 10 at a positionfacing the second magnet part 213 is effective to move the correctiontarget tooth 50 in the buccal side direction or the lingual sidedirection while obliquely moving the correction target tooth 50 asdescribed in FIG. 14. The support member 31 illustrated in FIG. 15 isapplicable to the variations illustrated in FIG. 16 or FIG. 17 withappropriate modification of the design of the support member 31illustrated in FIG. 15.

In the embodiment described above, the transparent resin from which thegrip member is made may contain carbon. With this configuration, thegripping forces of the first piece 20 and the second piece 10 can beenhanced, so that more stable anchorage is ensured, and movement of thecorrection target tooth in a desired direction by the force applyingmember can be further ensured. When the grip member made of atransparent resin is used as an aligner, carbon is partially used sothat a portion which is preferably flexible and a portion which ispreferably non-flexible are formed to have the same resin thickness. Inthis way, it is also possible to handle movement of a long tooth rowdepending on the condition of the tooth row of a patient.

In the embodiment described above, a configuration including theabove-described first piece 20, the above-described second piece 10, andthe force applying member 30 placed to connect the first piece 20 to thesecond piece 10 has been described. However, for example, aconfiguration in which the first piece 20 is not connected to the secondpiece 10, that is, a configuration in which the first piece 20 gripping,for example, the correction target tooth is independent of the secondpiece can also move the correction target tooth gripped by the firstpiece 20 in a desired direction by using, for example, the known setscrew described above as a force applying member and implanted in adesirable position of the first piece 20 while the anchorage of thesecond piece 10 is ensured. As described above, correction is performedwith the screw being directly in contact with the correction targettooth. Therefore, a flexible material such as a cap made of, for examplea resin or rubber is preferably attached to the distal end of the screw.This is to protect the correction target tooth.

The set screw used as an example in the above-described embodiment isapplicable not only in the correction device according to the presentembodiment of the present invention but also other orthodonticcorrection devices such as expansion screws used, for example, forexpansion plates.

Cases using the correction devices described in the above embodimentwill be described below.

FIGS. 18( a)-18(d), FIGS. 19( a)-19(d), and FIGS. 20( a)-20(d) arepictures showing cases 1-3 in each of which the correction deviceaccording to an embodiment of the present invention is used. In each ofthe pictures of cases 1-3, a broken line is shown so as to clearlyindicate that the first piece and the second piece of the correctiondevice are separated.

FIGS. 18( a)-18(d) show case 1 in which the correction device is usedfor the upper jaw of a patient. Specifically, FIG. 18( a) shows a statebefore treatment in which the correction device is not placed. In thisstate, it can be seen that between the third tooth and the fifth toothfrom the back on the right in the plane of the paper, there is no spacefor the fourth tooth which is in the course of the eruption. In such astate, exodontics is often selected to ensure a space for the eruption.However, in case 1, placing the device to cause distal movement of thethree teeth from the back was selected. As illustrated in FIG. 18( b),the correction device was placed and the treatment was started.Specifically, a grip member formed to fit the shape of the oral cavityon the upper jaw side of the patient was cut into a piece for grippingthe three teeth from the back on the right in the figure and a piece forgripping the other entire teeth. A screw was provided as a forceapplying member to connect the pieces. Here, the screw is turned littleby little for days. As a result, in FIG. 18( c) which shows a state inthe course of the treatment and in which the correction device isplaced, it can be seen that the three teeth from the back on the rightin the plane of the paper gradually moved in a mesial direction (in aback direction), and finally, as shown in FIG. 18( d), a space for theeruption of the fourth tooth is ensured.

FIGS. 19( a)-19(d) show case 2 using the correction device for the lowerjaw of the patient. Specifically, in FIG. 19( a) which shows a statebefore treatment and in which no correction device is placed, it can beseen that the width between the left tooth row and the right tooth rowis narrow, and thus no sufficient space is provided for four front teethon the upper side in the figure and thus, the four front teeth aremisaligned. The correction device was placed as illustrated in FIG. 19(b) and the correction was started. Specifically, a grip member formed tofit the inner shape of the oral cavity on the lower jaw side of apatient was cut at the upper center in the plane of the paper intopieces which grip neither the four front teeth nor teeth on both side ofthe four front teeth, but each grip the remaining teeth which arelocated symmetrically on the right and the left. A screw as a forceapplying member was provided to connect the pieces. The screw wasprovided on portions extending from the pieces gripping the remainingteeth located symmetrically on the right and the left to the lingualside of the front teeth, and horizontal movement of the left tooth rowand the right tooth row was uniformly caused to increase the widththerebetween. Here, when the screw was turned little by little for days,as FIG. 19( c) shows a state after the correction and in which device isplaced, the remaining teeth located symmetrically on the right and theleft in the figure moved to the buccal side. As a result, it can be seenthat the space for the four front teeth was ensured, and the four teethwere aligned and corrected (see also FIG. 19( d) which shows a stateafter the treatment and in which no correction device is placed).

FIGS. 20( a)-20(d) show case 3 in which the correction device is usedfor the upper jaw of a patient. Specifically, FIG. 20( a) shows a statewhich is before treatment and in which no correction device is placed.In this state, it can be seen that the second to sixth teeth from theback located on the left in the figure are displaced to the lingualside. As illustrated in FIG. 20( b), the correction device was placed,and treatment was started. Specifically, a grip member formed to fit tothe inner shape of the oral cavity on the upper jaw of a patient was cutinto pieces at a position near the sixth tooth from the back located onthe left in the figure, and a palate portion was cut at its center to besymmetric on the right and the left in the plane of the paper. A screwas a force applying member was provided to connect the pieces to eachother. Here, two screws were provided along the cut line. The two screwsere termed little by little for days. From FIG. 20( c) which shows astate after the treatment and in which the correction device is placed,it can be seen that the second to sixth teeth located on the left in thefigure moved to the buccal side (see also FIG. 20( d) which shows astate after the treatment and in which no is placed).

As described above, as illustrated cases 1-3 of FIGS. 18( a)-18(d),FIGS. 19( a)-19(d), and FIGS. 20( a)-20(d), when the correction deviceof the present invention is used, a correction target tooth gripped bythe grip member can be reliably moved in a desired direction by theforce applying member while at least one of the first piece or thesecond piece which form the grip member and independent of each other isused as a strong anchorage. When the device is divided at its centerinto left and right pieces to obtain the first piece and the secondpiece having a same size, the left and right tooth rows can be uniformlyand reliably moved by opposite force from the force applying member. Inthis way, the correction device can easily and reliably move thecorrection target tooth in a desired direction while ensuring asatisfactory anchorage. So that highly predictable treatment can berealized.

INDUSTRIAL APPLICABILITY

The present invention is useful in the field of orthodontics.

1. A correction device for moving a correction target tooth of a patientin a desirable direction, the correction device comprising: a gripmember formed to fit to an inner shape of an oral cavity of the patientso as to grip and cover a tooth row of the patient, gum parts, andalveolar bone parts on both of a buccal side and a lingual side of thetooth row, wherein the grip member includes a first piece, and a secondpiece independent of the first piece, and a force applying memberprovided to connect the first piece to the second piece and configuredto move the correction target tooth in the desired direction is furtherprovided.
 2. The correction device of claim 1, wherein when thecorrection device is used on an upper jaw side, the grip member furtherincludes a palate portion continuous with a portion covering thealveolar bone part on a lingual side of the tooth row and formed to fitto a shape of a palate.
 3. The correction device of claim 1, wherein thefirst piece grips the correction target tooth to cover an area extendingfrom a crown part to a periphery of a cervical part of a tooth row ofthe patient, and the second piece covers an area extending from a crownpart to a periphery of a cervical part of a tooth row of the patient. 4.The correction device of claim 3, wherein a skeletal anchor is implantedin the second piece.
 5. The correction device of claim 1, wherein thefirst piece grips the correction target tooth to cover an area extendingfrom a crown part to a periphery of a cervical part of a tooth row of apatient, the second piece grips a correction target tooth, which isdifferent from the correction target tooth gripped by the first piece,to cover an area extending from a crown part to a periphery of acervical part of a tooth row of the patient, and when the correctiondevice is used for a lower jaw, the first piece and the second pieceextend to positions close to front teeth, and the force applying memberis positioned near the front teeth.
 6. The correction device of claim 2,wherein the first piece grips the correction target tooth to cover anarea extending from a crown part to a periphery of a cervical part of atooth row of a patient, the second piece grips a correction targettooth, which is different from the correction target tooth gripped bythe first piece, to cover an area extending from a crown part to aperiphery of a cervical part of a tooth row of the patient, and when thecorrection device is used for an upper jaw, the force applying member isprovided on the palate portion.
 7. The correction device of claim 6,further comprising: a third piece forming the grip member, formedindependently of and near the first piece and the second piece, andcovering an area extending from the crown part to the periphery of thecervical part of a tooth row of the patient; and a fixing memberconnected to the force applying member and extending from the forceapplying member to the third piece.
 8. The correction device of claim 1,wherein the first piece grips the correction target tooth to cover anarea extending from the crown part to the periphery of the cervical partof a tooth row of the patient, and a skeletal anchor is implanted in thesecond piece.
 9. The correction device of claim 1, wherein the desireddirection is a distal or mesial direction, a lingual side or buccal sidedirection, or an upward or downward direction with respect to the toothrow.
 10. The correction device of any one of claims 9, wherein whenthere is a correction target tooth to be obliquely moved in the lingualside or buccal side direction, a portion of the grip member covering thecrown part of the correction target tooth to be obliquely moved isremoved on the buccal side or the lingual side.
 11. The correctiondevice of claim 1, wherein the force applying member is a wire, a screw,a spring, an orthodontic rubber, or a magnet.
 12. The correction deviceof claim 11, wherein the screw, the spring, the orthodontic rubber, orthe magnet may be provided to extend over the first piece and the secondpiece in a direction corresponding to the desired direction.
 13. Thecorrection device of claim 12, wherein the first piece and the secondpiece each has a portion into which a screw, spring, orthodontic rubber,or a magnet is incorporated, and the portion is formed as a thick part.14. The correction device of claim 1, wherein the grip member is made ofa transparent resin.
 15. The correction device of claim 14, wherein thegrip member preferably has a portion having a two-layer structure, andthe portion having the two-layer structure includes a lower layer whichis a membrane sheet made of silicon and an upper layer made of thetransparent resin.
 16. The correction device of claim 14, wherein thetransparent resin contains carbon.
 17. The correction device of claim 1,wherein the grip member covers a region including the tooth row, the gumparts, and highest contour portions of the alveolar bone part on thebuccal side of the tooth row.
 18. The correction device of claim 1,wherein the grip member is configured to grip the entire tooth row of apatient.
 19. The correction device of claim 1, wherein the first pieceis used for the upper jaw, and covers an area extending from the crownpart to the periphery of the cervical part of the entire tooth row ofthe upper jaw of the patient, the second piece is used for the lowerjaw, and covers an area extending from the crown part to the peripheryof the cervical part of the entire tooth row of the lower jaw of thepatient, and the force applying member is an intermaxillary rubber. 20.The correction device of claim 19, wherein a skeletal anchor may beimplanted in both or one of the first piece and the second piece.